Process of recovering ammonium sulfate from gas.



H. KGPPERS. PROCESS OF REGDVERING AMMONIUM SULFATE PROM GAS. APPLIUATIONFILED JAN. 15. 1908- 953,959. Patented Ap r.5,1910.

W arm W UNITED STATES PATENT Prion.

PROCESS OF RECOVERING AMMGNIUM SULFATE FRQM Grits.

Specification of Letters Patent.

. l a tented ilnp'r. 5, Elli-lit).

Application filed January 15,,1908. Serial No. 10,874.

To all whom it may concern:

lle it known that l, llnxmczr Korrsns,

a citizen of Germany, residing at Essenpin the-Ruhr, Germany, haveinvented new and usefullmprovementsinProcesses of Recov cring AmmoniumSulfate from Gas, of which the following is a specification,

From th* ammonia 'atcr resulting from cooling and washing-the gases oithe dry distillation or gns'ification of organic substances, a salt isobtained by driving oil the ammonia in a distilling column and treatingthe resulting vapors with sulfuric acid. As owing to the chemicalreaction which thus takes place, the diluting Water of the acid isvaporized, and as but the steam carrying the ammonia should be given offto the atmos phcre, or, in other Words, as the reaction should takeplace at atmospheric pressure it is necessary to maintain thetemperature above the boiling point. This high temperature in practiceat least- 150 C.) has the objection that the ammonium sulfate is readilydecomposed or dis'associatcd, and

that the affinity of the ammoniato the su] furic acid diniinisl es withthe rising of the temperature. This incurs on the one hand a creased.

loss of ammonimwhile on the other hand the percentage of free acidiii-the salt is in- The present invention relates to a process ofobtaining ammonia from gases, which can be carried out at a suitabletemperature below the boiling poi it,(,

According to my invention the vapors ot' the distilling column arepiixedwith a slittic'ient uantity of an'elativcly dry gas, so thata terthereaction with the acid, not pure steam, but a gas and steam mixture rc-Ineins. As according to the law of Dalton, the steam in this mixturepossesses but it partial pressure, which ctnrcsponds to a temperaturebeneath the boiling point, it is only lnecessaryjo maintain thistemperature,

which may be reduced at pleasure by the addltlon of the raretynig gases,The addition of these gases FOI'I'ESPOIlClS therefore to the carryingout of the process in a more or less complete vacnurmthc use of which iscoupled with practical difficulties The nature of the gases isimmaterial as long as they remain chemically inditterent. Thus, forexample, air (i'litrogen) may be used as well of course as thedistillation gas'itself. i

The accompanying drawing represents a side elevation, partly in section,of an apparatus For carrying my process into clt'ect.

The distillation chamber 10 is by raising pipe 11 connected to ahydraulic main 12,

This cooler receives water from connection 15, which water flows throughthe cooler pipes l6 and is by connection 17 conveyed to an accunnilat'oror return device (not shown). Cooler ll is by pipe 18 connected to firstwasher '11). which. iii-turn, by pipe 20 lsconnuctcd to a second washer2t, from whit h leads pipe 22. Washer 21 is by pipe sprayed with freshwater, and is provided at its bottofm with an outlet pipe 24 leading toan accumulator 25. term the latter a pump 26 convoys theliq'uid throughpipe 27 to washer 19. This washer has an outlet pipe 28 leading to aseparator 29. which is provided with an ovcrtlow 30 leading to tarreceptacle ilh-ann an overflow 232 leading to ans-water. reccplaclcfl l.The space in cooler 14 surrounding pipes 16 is. by overflow 3st and pipe235, also connected to separator 29.

From receptacle s3 a pump 36 hits the annnonia 'ater through pipe 37 tothe distilling column :16. This column contains hoods 39 from which theliquid, descends from compartment to compartnumt. lnto column 38 enterssteam tccd pipe ll) and pipe 41 for introducing lime or any other basicsubstance. (olumn 538 is by pipe l2 connected to saturation vessel 4such pipe opening into a. ring 4-l having apertures 45 and located atthe bottom of vessel 43. In .a bottom recess H3 is placed an injector l?for the removal of the separated salt. b aturation vessel -13 is bypipes -18, 49 con ncctcd to the foundation channel .30 of the distillingchamber l0, and is provided with a discharp'c'pipc 31.

The operation is as follows: The gases generated in distilling chamber10, are in cooler ll, cooled as much as possible during which opt-rationrated.

The water will at the samctime wash (all a corrcspmiding quantity of armmonia, so that a mixture of ammonia water and tar is conveyed t'b 'oug'hpipe 37 into separator 25). In washers l5) and 21, the rest of theammonia contained in the gas is washed out, this washing being,effected. in washer Ll by-t'rcsh water, and in washer 19 by thedisclmrsz'c water of washer 21, ulrcady enriched by ammonia. Theannuonia water from washer 19 also flows into the separator 21), where,by specific gravity, a l separation of annnonia water and tar takes fromwhich a pipe l-Ll leads to a cooler 14s how over into the tar receptacle31. With the fixed ammonia, that is the ammonia already bound in the rawgas with ac1ds,'1s de- I thus comprise a mixture of steam and amammoniasalt in solid form, another circumthe salt sinks with the temperature.

sulfuric acid, passes out through discharge place. The former will flowover into the gas water receptacle 33, while the latter will in thedistilling column 38, the free ammonia is driven oil by steam, whilesimultaneously composed by lime or other basic substance introdudedthrou 'h pi e 41.

The vapors of distil ing column 38, which pipe 51. The separated salt israised by inector 47 and is dried by a centrifugal machine or otherwise.

Besides the advantages already described, such as the production of analmost neutral stance is of considerable practical importance. By thelowering pf the temperature the quantity of ammonia salt dissolved inthe acid bath is reduced, as the solubility of The solution thereforeremains more mobile and offers better contact to the penetrating gases ithan a bath composed of a thick liquld. In i this Way the proportion offree acid in the resulting, salt is reduced, while the pressure requiredfor overcoming the resistance of the, bath is diminished;

I claim: I

1. Process of obtaining ammonia and tar from gases of the dry;distillation or gasification/of fuels, which consists in cooling saidgases to form acondensate of tar and water,

separating the tar therefrom,-scrubbing the I gas with Water to form anaqueous solution of ammonia, passing said condensate and aqueoussolution through a distilling columnto separate the ammonia, mixing thevapors leaving the distilling column with a rarefying' gas, andconducting the resulting mixture to/a saturation bath.

2. Process of obtainin from gases of the dry dlstillation orgasification 01% iuels, which consists in cooling said gases to form acondensate of tar and water,

separating the tar therefrom, scrubbing the gas with water to form anaqueous solution of ammonia, passin said condensate and aqueous solutionthrough a distilling column to separate the ammonia, mixing the vaporsleaving the distilling column with preheated air, and conducting theresulting mixture to a saturation bath. v

Signed by me at Chicago, Illinois, this 11 day of January, 1908.

EINRICH- KoPrEns.

Witnesses:

M. ErFnxNn, A. FLrNN.

ammonia i and tar

